Definitely not being charged by the motorhome.
For troubleshooting, this is a quick and dirty way to check the wiring.
Start the motorhome. With the cable disconnected, check the voltage between Pins 1 and 4 as shown in the diagram below. Should read ~13.5 volts. If not, there should be a fuse inside the motorhome engine compartment fuse block identified as "towing" or similar.
If so, then the problem isn't on the motorhome end.
If you're using a Roadmaster 6 pin connector, here's how it is wired:
At the connector on the Jeep, check between Pins 2 and 5. You should read about 12.6 Volts. If not, there should be a fuse inside the engine compartment near the battery going to the Roadmaster connector.
If both of these are fine, check the wiring on the cable that connects the motorhome to the Jeep.
FWIW, I just recently added the charging wiring to our Jeep. The Roadmaster EvenBrake 9400 would drain the Jeep's battery after a few hours. Now after driving 10+ hours, no issues at all. I put the fuse right at the battery, and identified it with a label.
Good luck!
